The differences between RGB and CMYK

RGB

Both RGB and CMYK represent abbreviations of two types of color systems. The main difference between RGB and CMYK is that the first one is used for digital appearance and the second one is representative for the print world.

CMYK

The CMYK color system stands for CYAN, MAGENTA, YELLOW and K is for BLACK. By combining 100%Cyan+100%Magenta+100%Yellow= a Black that is not 100% pure Black, but a dark gray. By adding the K (Black) to the color system, the result will be a perfect Black, just like in RGB’s case, when the result of the three colors combination is 100% white.

Differences

So, if anyone starts a design in color and intends to keep it in the digital world, it’s ok to use the RGB mode, no matter what program you use, Photoshop, Adobe Illustrator, Corel Draw or Quark Express.
But, if your work is for printing purposes, the best way is to convert it to CMYK mode first, to take a look at the way it will show on paper. Anyway, it’s impossible to obtain a perfect match between an image that you see on a computer monitor (for instance) and the same image on print. In this case, there are some points to take into consideration that can affect the colors of the image on the paper: the way the monitor settings are made, the paper’s quality, its white degree, if it’s shiny or flat. Even if it’s impossible, you can obtain the closest match to the screen as possible by changing/converting the file mode to CMYK. Here are two examples for Photoshop and Adobe Illustrator.